1. Field of the Invention
This invention relates to an application of a treadmill and relates particularly to a buffer board structure of a treadmill.
2. Description of the Related Art
Generally, a treadmill uses a buffer board as a support below a belt. Because a quite large treading force is imparted to the buffer board when a user runs the treadmill, no buffer bounce will make the user quite uncomfortable. In this regard, it is common to install a buffer cushion and a buffer mechanism under the buffer board, stick a foam layer to the buffer board and then stick a woven layer to the foam layer. The aforesaid arrangement allows the belt to operate smoothly and provides a buffering effect with comfort.
However, the user easily treads on a same position and repeats his treading action, and in the long term this problem may cause the foam layer to collapse permanently. This collapse renders the foam layer unable to retrieve and lose the buffering effect.
This novel invention is made to improve a prior art issued by Taiwan patent No. TWI406686, and this invention and the prior art have the common inventor. The prior art comprises a treadmill buffer board which includes bamboo strips having the appropriate thickness and width. The bamboo strips are classified into longitudinal bamboo strips and latitudinal bamboo strips. At least one longitudinal bamboo strip and at least one latitudinal bamboo strip can be crossed each other and woven into a woven bamboo plywood board. The bamboo plywood board can be superimposed by a desired thickness to construct a woven bamboo laminated plywood board, thereby enhancing the strength and keeping the buffer bounce. Further, the prior art can directly put the longitudinal bamboo strips which are attached side by side over the latitudinal bamboo strip which are attached side by side to construct a stacking bamboo plywood board.
The aforesaid structures are all made of bamboo. After the prior art makes the bamboo laminated plywood board by weaving or superimposing or mixes the aforesaid two kinds of bamboo plywood boards, gaps formed between contact faces of the adjacent bamboo laminated plywood boards are uneven. Thus, distinct gap sizes are obviously formed when adhesives are laid on the contact faces. These gap sizes need to be filled in by adhesives. When the adhesives dry and solidify, the adhesives at respective adhesive positions between the bamboo laminated plywood boards have different amount of dryness and solidification. This situation causes the bamboo laminated plywood boards to have more rigidity and causes an uneven treading buffer. If this structure is applied to a buffer board of a treadmill, the buffering effect will be decreased.
The aforesaid bamboo laminated plywood boards are mainly put one over another and attached by adhesives. When the plywood board is trodden to create a buffer effect, the dryness and solidification causes the adhesives to split easily and the direct contact between the adjacent plywood boards creates friction and incurs noises.
The weaving or superimposing process of bamboo sheets may take time and require a larger amount of adhesives to fill in the larger gaps so that bamboo laminated plywood boards can be completed. This, however, cannot save costs.